- #1
Red Dog
- 3
- 0
Can anyone help me with a formula to calculate the output of an airlift pump for a certain head, pipe diameter and pipe length?
An air lift pump works on the principle of a fill/empty cycle (so many seconds to fill and so many to empty). I can calculate the pressure required for a particular height.
The higher the water is to be pumped, the longer the pump time has to be, but I can't work out if this is because of the height or the pipe length or a combination of the two.
If for example, at the pump, with a 1 metre head, The fill time is 5 seconds and the pump time is 10 seconds. At a height of 40 metres, the pump time for the same volume of water increases to around 45 seconds.
However, at the outlet (open, no restriction) the flow period is reduced and the pause until the next flow event increases. I understand that a part of the pump time will be used to overcome inertia and the weight of the water already in the delivery pipe.
The pumping design is that a canister has a non-return valve at the entry point. There is a delivery pipe reaching almost to the bottom inside the canister with a non-return valve on top. Compressed air flows into the canister and acts on the surface of the water, forcing it down and up the delivery pipe. The air flow is time controlled to stop before the canister is completely empty. The air is then exhausted from the canister, allowing more water to refill it before the next pump cycle.
I would like to be able to enter values for:
Canister volume
Head (height)
Delivery pipe diameter
Delivery pipe length
Operating air pressure
To calculate what the pump time would be.
From this I could then work out an estimated flow rate for a particular sized canister under those operating conditions.
I cannot find any formulae for normal flow/volume that will give this information.
Any help would be greatly appreciated, as I have been wrestling with this for some time.
Thanks
An air lift pump works on the principle of a fill/empty cycle (so many seconds to fill and so many to empty). I can calculate the pressure required for a particular height.
The higher the water is to be pumped, the longer the pump time has to be, but I can't work out if this is because of the height or the pipe length or a combination of the two.
If for example, at the pump, with a 1 metre head, The fill time is 5 seconds and the pump time is 10 seconds. At a height of 40 metres, the pump time for the same volume of water increases to around 45 seconds.
However, at the outlet (open, no restriction) the flow period is reduced and the pause until the next flow event increases. I understand that a part of the pump time will be used to overcome inertia and the weight of the water already in the delivery pipe.
The pumping design is that a canister has a non-return valve at the entry point. There is a delivery pipe reaching almost to the bottom inside the canister with a non-return valve on top. Compressed air flows into the canister and acts on the surface of the water, forcing it down and up the delivery pipe. The air flow is time controlled to stop before the canister is completely empty. The air is then exhausted from the canister, allowing more water to refill it before the next pump cycle.
I would like to be able to enter values for:
Canister volume
Head (height)
Delivery pipe diameter
Delivery pipe length
Operating air pressure
To calculate what the pump time would be.
From this I could then work out an estimated flow rate for a particular sized canister under those operating conditions.
I cannot find any formulae for normal flow/volume that will give this information.
Any help would be greatly appreciated, as I have been wrestling with this for some time.
Thanks